I've never played the original X-Com, but if UFOAI is anything like it, I definitely agree with its legendary reputation. Though still quite incomplete, its basic gameplay is already incredible, managing squads step by step through overlapping reaction fire and praying as each shot goes off is absolutely nailbiting, and while the graphics look like something from 1998, they look like something clean and professional from 1998. If UFOAI matures as much as Wesnoth has, it'll definitely be world-class.